Physical Science 8th grade (1).pdf

A an atom with 11 protons 11 electrons and 13

Info icon This preview shows pages 144–147. Sign up to view the full content.

View Full Document Right Arrow Icon
a. An atom with 11 protons, 11 electrons and 13 neutrons b. An atom with 12 protons, 11 electrons and 12 neutrons c. An atom with 13 protons, 13 electrons and 13 neutrons d. An atom with 13 protons, 13 electrons and 14 neutrons 4. Identify the following nuclear changes as alpha decay or beta decay. a. A radium atom with 88 protons and 138 neutrons becomes a radon atom with 86 protons and 136 neutrons. b. A sodium atom with 11 protons and 13 neutrons becomes a magnesium atom with 12 protons and 12 neutrons. Section 6.2 5. Electrons “X” and “Y” are temporarily on different energy levels. As they fall back toward ground state, X emits red light and Y emits blue light. Which electron had more energy before falling? Particle Place in Atom Charge Relative Mass electron proton neutron
Image of page 144

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chapter 7 Elements and the Periodic Table What are metals like? Think of things that are made with metals like aluminum, copper, iron, and gold. What do they have in common? They are usually shiny, and they can often be bent into different shapes without breaking. Did you know there is a metal that is shiny, but is so soft it can be cut with a knife? This metal is very reactive. If you place a piece of this metal in water, it will race around the surface, and the heat given off is often enough to melt the metal and ignite the hydrogen gas that is produced! This strange metal is called sodium. You can look at the periodic table of elements to find other metals that behave like sodium. In this chapter, you will become familiar with how you can predict the properties of different elements by their location on the periodic table. 1. Why are the elements arranged in the periodic table? 2. What sort of information can the periodic table of elements give you? 3. Why does the periodic table have the shape that it does?
Image of page 145
138 U NIT 3: A TOMS AND THE P ERIODIC T ABLE Figure 7.1: Rusting is an example of a chemical change. physical properties - characteristics of matter that can be seen through direct observation such as density, melting point, and boiling point. chemical properties - characteristics of matter that can only be observed when one substance changes into a different substance, such as iron into rust. 7.1 The Periodic Table of the Elements Before scientists understood how atoms were put together they were able to identify elements by their chemical properties. In this section, you learn how the elements are organized in the periodic table , and how an element’s chemical properties are related to the arrangement of electrons. Physical and chemical properties Physical properties Characteristics that you can see through direct observation are called physical properties . For example, water is a colorless, odorless substance that exists as a liquid at room temperature. Gold is shiny, exists as a solid at room temperature, and can be hammered into very thin sheets. Physical properties include color, texture, density, brittleness, and state (solid, liquid, or gas). Melting point, boiling point, and specific heat are also physical properties.
Image of page 146

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 147
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern